Computers may receive input in a variety of ways, including, by means of a keyboard, mouse or computer input area. Computer input areas generally take one of two forms—i.e., that of a touch pad comprising discrete touch sensors (e.g., a touch pad comprising an array of capacitive sensors), or that of a touch pad or other perimeter sensor comprising sets of intersecting detection paths (e.g., a touch pad comprising first and second intersecting sets of optical detection paths).
Touch pads that overlay display screens such as liquid crystal displays (LCDs) are becoming more and more popular in a variety of devices, including personal digital assistants (PDAs), mobile phones, automated teller machines (ATMs), and point-of-sale terminals.